I. Field of the Invention:
The present invention relates to a heat exchanger element arranged in a casing, preferably for a gaseous medium, e.g. air, and a liquid medium, e.g. water.
II. Description of the Prior Art:
In the case of such heat exchangers having an exchanger element, e.g. serving as a heat carrier arranged in a casing, while the medium to be heated flows through the latter, while there is a flow around the exchanger element, it is known to use as the exchanger element a tube assembly made from rigid plastic tubes. Accompanied by reciprocal spacing, the individual plastic tubes fill the cross-section of the casing and the medium to be heated flows through the latter, while also flowing around the plastic tubes (DOS No. 2,617,353). The combination of both ends of the assembly with tube connections forming two opposite walls of the casing through which the medium to be heated flows and in which the individual tube ends are received, while being reciprocally sealed. These tube connections are connected to the inlet and the outlet of the medium flowing through the heat exchanger. The individual tubes of the tube assembly are self-supporting, so that their spacing in the casing is automatically maintained. German Pat. No. 2,012,883 also discloses a tubular heat exchanger in which the tube assembly serving as a heat carrier and filling the cross-section of the casing comprises a mat formed from rigid tubes, whose spacing is maintained and which are interconnected by wires and is wound into a reel. This mat is provided with deflection members used for guiding the medium to be heated.
These known tubular exchangers are so-called crossflow-type exchanges, in which the medium to be heated is directed at right angles to the tubes and flows around the latter. With regards to their efficiency, such crossflow-type exchangers occupy a position between parallel flow and counter-current exchanges, in which the media involved in the heat exchanger are moved in the same or opposite directions, the counter-current exchanger having the highest efficiency.
The known tubular heat exchangers have disadvantages regarding their manufacture and installation, as well as their possible uses. The construction and installation of the exchanger element comprising tubes in the casing are complicated and lead to special problems, which are mainly due to the necessary combination of the two tube ends to form tube connections or sockets in the casing wall for the medium flowing through the exchanger element. The combination of the tube ends to form a leak-proof tube connection or socket requires special care and takes a considerable amount of time. The known tubular heat exchangers, with their casing and the exchanger element incorporated therein, form an invariable unit, which must be incorporated into the line carrying the medium to be heated and whose construction is invariably fixed to specific operating conditions and values, so that differently designed heat exchangers must be provided for different operating conditions. In addition, the efficiency of these known tubular heat exchangers does not satisfactorily take into account the present-day requirements for energy saving.
This invention seeks to eliminate the disadvantages and problems linked with the known tubular heat exchangers and to provide an exchanger, which can be inexpensively manufactured and can be adapted with minimum expenditure to different operating conditions and requirements. It is also desirable that the invention provide a problem-free connection of the exchanger element to the medium flowing through it and better operating efficiency.
In connection with a heat exchanger according to the preamble of the main claim, this problem is solved by the features protected in its characterizing part.
The sub-claims represent advantageous further developments of the invention according to the main claim.